1. Field of the Invention
The present invention relates to a display device and a driving method thereof.
2. Discussion of the Background
Display devices may include a plurality of pixels arranged in a matrix, whereby images are displayed by controlling the optical intensity of each of the pixels on the basis of predetermined luminance information. Among display devices, an organic light emitting display displays images by electrically exciting light emitting fluorescent materials. An organic light emitting display is self-luminous, may have low power consumption, a wide viewing angle, and good response speed of a pixel, and may easily display high-quality moving pictures.
Each pixel of the organic light emitting display includes an organic light emitting element and a transistor to drive the element. The transistor may be a thin film transistor (TFT). The TFT may be a crystalline silicon TFT, such as a poly-crystalline or micro-crystalline silicon TFT, or an amorphous silicon TFT in accordance with the type of active layer.
When the active layer of the TFT is formed, deviation in threshold voltages of the TFTs in a display panel may occur due to non-uniformity in a manufacturing process. When the deviation in the threshold voltages of the TFTs occur, the TFTs may allow currents of different intensities to flow with respect to the same gray voltage. As a result, brightness uniformity of a screen may deteriorate.